To make sure the indexing is not at fault, you can rebuild it.
Go to the start menu
Type indexing in the search box
Choose Indexing options
Check that your directory is in the indexed locations, if not use Modify
Then click Advanced
Then select rebuild.

It is better to do that when you can leave the computer alone for a while, if you are not using the computer, after a few minutes it will index at full speed, making it faster.